Today I woke early, and was catching up, and found this:
Naturally, as I am Catholic, it caught my eye.
The Crusades were a Defensive War. The Muslims were attacking an ally, who asked for our assistance. They were not that successful - as the Muslims kept re-grouping and re-attacking over many centuries. Although the Battle of Tours in October 762 (Christian forces led by Charles Martel, Charles the Hammer) stopped the Muslims from advancing further into France, they maintained their Iberian Peninsula foothold in Europe until 1492, when the combined forces of Ferdinand and Isabella finally pried loose Moors in the Battle of Granada.
The Muslims were, in the treaty, free to practice their religion, until 1502, when they were given a choice, convert or leave.
Beginning in Valencia in 1502, Muslims were offered the choice of baptism or exile. The majority decided to accept the former, becoming 'New Catholics', of very great interest to the newly established Spanish Inquisition, authorized byPope Sixtus IV in 1478.
The Morisco conversos (converts), though outwardly Catholic, continued to adhere to their old beliefs in private as crypto-Muslims in a practice known as taqiyyah or precaution, conduct allowed for by some Islamic authorities when the faithful are under duress or threat of life.
Some of the above I knew from college work - I specialized in Latin American History, and was reasonably fluent in Spanish, at that time. I cited Wikipedia (yes, I do know their woeful record of inaccuracy in many entries. However, they are generally a good resource for basic research - I sometimes use them for background in areas of science I need to brush up on. That would be Chemistry or Physics, NOT Climate Change).
The Muslim invaders weren't stopped from their Aggressive Wars until the Battle of Vienna:
...the other 9-11: September 11th, 1683, the day when an alliance of Christian armies led by Jan III Sobieski, the King of Poland, arrived at the Gates of Vienna.
The Ottoman Empire had been expanding into Europe ever since Constantinople fell to the Turks, and even before that. Wherever the Muslim armies went, they plundered cities, took slaves, turned churches into mosques, and converted many thousands of Christian captives to Islam at the point of a sword.
The Sultan’s armies overran Greece, Bulgaria, Romania, and Serbia. They turned Protestant Hungary into a compliant vassal and made war repeatedly on Austria and the Polish-Lithuanian Commonwealth. The Ottomans had designs on Vienna, since the fall of the city would open the way into the heart of Austria and the rich principalities of southern Germany.
The Gates of Vienna tells the stirring story on their blog. Do read it - you need to know why September 11 has significance, beyond 2001's atrocity.
Bonus - you'll learn the story of why we eat Croissants.